This invention relates to a high voltage circuit interrupter, and more particularly to a device for switching shunt reactors and shunt capacitor banks for voltage control and transmission line compensation.
Devices presently available to switch reactors and capacitor banks into and out of circuit with power transmission lines include disconnect switches, load break switches and circuit breakers. Interruption provided by a disconnect switch is not clean, and the switches are vulnerable to the weather which may effect their performance. Circuit breakers are costly devices. The low current load break switches require many interrupters in series, for example six interrupters at 550 kilovolts, and must be used with conventional disconnect switches. Moreover, the slowness of the disconnect switches present problems with synchronism between phases in a multi-phase transmission circuit. Transient voltage control resistors associated with disconnect switches are generally located external to the interrupter and are also vulnerable to the weather. Such resistors are generally inserted by the disconnect switch blade which travels at high velocity and must be precisely guided mechanically.
Two-pressure interrupters for switching reactors and shunt capacitors in a power transmission circuit require a high pressure gas system with a compressor, storage vessels having auxiliary heaters, and a complex valving system to provide the gas blast during circuit interruption. "Puffer" interrupters provide the high pressure gas blast through a piston and a cylinder where a fixed piston and a moving cylinder attached to the moving interrupter contact compresses the gas which is then directed to the area within the interrupter where arcing occurs. "Puffer" interrupters require high mechanical forces to compress the gas, thereby increasing mechanical loads, and requiring comparatively complex structure.
There is a need for a simplified high voltage circuit interrupter which reduces the number of required serial interrupters to break a high voltage circuit, and which substantially reduces the required mechanical complexity now seen in two-pressure and "puffer" interrupters.